This application is based on Application No. 2001-360753, filed in Japan on Nov. 27, 2001, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an electronic control device for an internal combustion engine wherein an atmospheric pressure relational value including the atmospheric pressure is determined by calculation from other control parameters for the internal combustion engine and the atmospheric pressure relational value is used as an auxiliary parameter for control.
2. Description of the Related Art
Conventionally, for example, as shown in Japanese Patent Laid-Open No. 5-312087, an electronic control device for an internal combustion engine has been well known, where the atmospheric pressure relational value including the atmospheric pressure is calculated based on the information of the intake air amount, rotational speed, charging efficiency, and throttle travel of the internal combustion engine.
Furthermore, for example, as shown in Japanese Patent Laid-Open No. 2001-132522, an electronic control device for an internal combustion engine has also been well known, where the atmospheric pressure relational value including the atmospheric pressure is calculated based on the information of the rotational speed, throttle travel, and intake tube pressure of the internal combustion engine. However, an electronic control device for an internal combustion engine which uses both the charging efficiency information or the like and the intake tube pressure information or the like to calculate the atmospheric pressure relational value including the atmospheric pressure has not yet been proposed.
By the way, such an arithmetic value of the atmospheric pressure relational value including the atmospheric pressure using the charging efficiency information or the like is determined according to a specified arithmetic expression which takes the ratio between the two dimensional map value of the charging efficiency corresponding to the rotational speed and the throttle travel in the previously set standard atmospheric condition or the relational value of the charging efficiency, and the actually measured charging efficiency, and therefore, an error depending on the body difference (load because of the difference in the piston-cylinder friction coefficient or the like) of each internal combustion engine may be caused.
The present invention is made to solve such problems, and it is an object to provide an electronic control device for an internal combustion engine wherein in the atmospheric pressure detecting system with no atmospheric pressure sensor, the information of the intake tube pressure and the information of the rotational speed, charging efficiency, and throttle travel are chosen and used depending on the operating area, and the arithmetic frequency and accuracy of the atmospheric pressure relational value in all operating areas can be raised.
The electronic control device for an internal combustion engine according to the present invention comprises: various kinds of sensors for detecting the operating state of the internal combustion engine; rotational speed detecting means for detecting the rotational speed of the above-described internal combustion engine; intake air amount detecting means for detecting the intake air flow rate of the above-described internal combustion engine; throttle travel detecting means for detecting the throttle travel of the above-described internal combustion engine; intake tube pressure detecting means for detecting the intake tube pressure of the above-described internal combustion engine; storing means in which the charging efficiency corresponding to the rotational speed and the throttle travel in the standard atmospheric condition is previously stored and set as a two-dimensional map, and which outputs the above-described stored and set value corresponding to the above-described rotational speed and the above-described throttle travel; and correcting means for correcting the atmospheric pressure relational value including the atmospheric pressure calculated based on the information of the intake air amount, rotational speed, charging efficiency, and throttle travel of the above-described internal combustion engine by using the atmospheric pressure relational value including the atmospheric pressure calculated based on the information of the rotational speed, throttle travel, intake tube pressure of the above-described internal combustion engine.
Furthermore, the electronic control device for an internal combustion engine according to the present invention is a device, wherein the above-described correcting means comprises: first arithmetic means for calculating the atmospheric pressure relational value including at least the atmospheric pressure value according to a specified arithmetic expression of taking a ratio between the charging efficiency determined by selectively using the intake air amount and rotational speed of the above-described internal combustion engine and the stored and set value outputted from the above-described storing means; second arithmetic means for calculating the atmospheric pressure relational value including at least the atmospheric pressure based on the intake tube pressure detected in the case of being in a specific operating state corresponding to the rotational speed, throttle travel, and intake tube pressure of the above-described internal combustion engine; and comparing means for comparing the arithmetic value obtained from the above-described first arithmetic means and the arithmetic value obtained from the above-described second arithmetic means, and the comparison result of the above-described comparing means is reflected to the arithmetic value obtained by the above-described first and second arithmetic means.